1. Technical Field
The present disclosure is directed to systems and methods for brush manufacture and, more particularly, to systems and methods that control grain orientation in components, assemblies and other articles of manufacture. Exemplary systems and methods disclosed herein utilize hot pressing techniques to enhance the properties and/or functionalities of brushes and other electrical components.
2. Background Art
In the field of motor design, a brush is provided to interact with, i.e., contact, a rotating commutator. Brushes are typically fabricated from carbon and/or copper-containing powder mixtures and brush design is generally recognized as being critical to the operation and durability of the motor assembly. A conventional method for manufacturing a graphite brush is disclosed in Japanese Laid-Open Patent Publication No. 90-51345. The brush is manufactured from a mixture of powders including an aluminum abrasive, molybdenum disulfide and tungsten disulfide, each powder consisting of particles having diameters of less than 50 μm. The powders are combined in a solution of adhesives, pulverized and prepared with powders having a diameter 100 μm. The total mixture is then compressed at a pressure of 0.25 tons/cm2 and fired at a temperature of 700° C.
U.S. Pat. No. 5,447,681 to Seung et al. discloses a method for manufacturing a metal graphite brush that includes the steps of preparing natural graphite powders, wet-mixing the graphite powders with adhesives, pulverizing the mixed powders to diameters of less than 200 μm, press-molding the powders under a pressure of 2-3 ton/cm2 and heating at a temperature 700° C. A lead wire is then attached to the press-molded component.
Despite efforts to date, techniques for fabrication of brushes imposes significant limitations on the design, geometry, structural features and properties/performance. Moreover, brushes and brush assemblies fabricated according to conventional processing techniques/methodologies are characterized by durability issues based, at least in part, on density limitations associated with conventional fabrication techniques. These and other shortcomings and limitations are overcome by the techniques, methods and articles of manufacture disclosed herein.